Here's a solution that requires no code.
1. Add a text box to your group header, and give it these properties:
Name txtHeadCount
Control Source =1
Running Sum Over Group
Format General Number
Visible No
2. Add a text box to the Detail section.
Size it to cover the entire Detail section, and Send To Back.
Choose Conditional Formatting on the Format menu.
Set Condition 1 to:
Expression ... [txtProductCount] Mod 2=0
and choose the shading color you want from the bucket.
3. Set the BackStyle of the other text boxes in the detail section to
Transparent.
How it works
The running-sum text box accumulates 1 each time there is a new header.
The Mod operator tests the left over when you divide by 2. The remainder
will be 0 every second time, so the big text box behind everything else in
the detail section is shaded every 2nd group.
I've seen examples on how to shade every other detail, I was wondering
if there is an easy way to shade every other group.
Just note: I'm not great with VB, so if thats the route I have to take,
please be very specific and dumb it down for me.